watchdog: MediaTek: add watchdog driver for MediaTek SoCs

This patch adds a common driver for the Mediatek SoC integrated
watchdog.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Tested-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 4796da0..4a9ebb6 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -103,6 +103,14 @@
 	   Select this to enable Cadence watchdog timer, which can be found on some
 	   Xilinx Microzed Platform.
 
+config WDT_MTK
+	bool "MediaTek watchdog timer support"
+	depends on WDT && ARCH_MEDIATEK
+	help
+	  Select this to enable watchdog timer for MediaTek SoCs.
+	  The watchdog timer is stopped when initialized.
+	  It performs full SoC reset.
+
 config XILINX_TB_WATCHDOG
 	bool "Xilinx Axi watchdog timer support"
 	depends on WDT